Short Biography of Imam Musa al-Kazim
(This is) an account of the Imam who undertook (the office) (al-qa'im) after Abu Abd Allah Ja'far b. Muhammad, peace be on them, (describing) who gave birth to him and the date of his birth. (It includes) the evidence for his Imamate, the age he reached and the period of his succession (khilafa), his death, its cause, and the place of his grave.
As we have mentioned before, the Imam after Abu Abd Allah Jafar, peace be on him, was Abu al-Hasan Musa b. Jafars the righteous worshipper (of God), peace be on him, because the qualities of outstanding merit and perfection were gathered in him, because of the designation (nass) by his father of the Imamate (being) for him, and his clear indication of it being his.
His birth took place at al-Abwa' in the year 128 A.H. (745/6). He, peace be on him, died in the prison of al-Sindi b. Shahik on the 6th of (the month of) Rajab in the year 183 A.H. (799). He was then fifty-five years of age. His mother was a slave-wife named Hamida al-Barbariyya. The period of his succession and occupying the office of the Imamate after his father, peace be on them, was thirty-five years.
His kunyas were Abu-Ibrahim, Abu al-Hasan and Abu Ali;. He is known as al-Abd al-Salah (the pious worshipper of God) and also he is described as al-Kazim (the restrained), peace be on him.